Vented sand core for sand casting

Abstract

In one example, a sand core for use in a sand casting process includes a core body including a sand composition, the sand composition including sand and a binder; and a burnable fuse extending within the core body along a path and out of a surface of the core body, wherein the burnable fuse is configured such that when the fuse is ignited, the fuse burns within the core body to substantially remove the fuse and form a venting tunnel along the path within the core body with an opening in the surface.

The invention claimed is: 
     
       1. A precursor sand core for use in a sand casting process, the precursor sand core comprising:
 a core body comprising a sand composition, the sand composition including sand and a binder; and 
 a burnable fuse extending within the core body along a path and out of a surface of the core body, wherein the burnable fuse is configured such that when the fuse is ignited, the fuse burns and the burning propagates along a length of the fuse within the core body to substantially remove the fuse to form a venting tunnel along the path within the core body with an opening in the surface, wherein the burnable fuse is configured to burn at approximately 1 foot per minute or greater when ignited. 
 
     
     
       2. The precursor sand core of  claim 1 , wherein the venting tunnel is configured such that gas generated within the core body during a sand casting process using the sand core escapes the core body via the venting tunnel. 
     
     
       3. The precursor sand core of  claim 1 , wherein the path of the burnable fuse is non-linear. 
     
     
       4. The precursor sand core of  claim 1 , wherein the burnable fuse is configured to burn along substantially an entire length of the burnable fuse within the core body. 
     
     
       5. The precursor sand core of  claim 1 , wherein the burnable fuse comprises a black powder core and at least one outer layer around the black powder core. 
     
     
       6. The precursor sand core of  claim 1 , wherein the venting tunnel has substantially a same diameter as the burnable fuse. 
     
     
       7. The precursor sand core of  claim 1 , wherein the path of the burnable fuse extends in substantially a center of the core body. 
     
     
       8. The precursor sand core of  claim 1 , wherein the burnable fuse extends out of the surface at a first location and a second location such that the venting tunnel formed by burning the fuse includes two separate openings in the surface. 
     
     
       9. The precursor sand core of  claim 1 , wherein the burnable fuse exhibits a diameter of greater than approximately 1.5 millimeters. 
     
     
       10. The precursor sand core of  claim 1 , wherein the burnable fuse comprises a fuel source and an oxidizer. 
     
     
       11. The precursor sand core of  claim 1 , wherein the burnable fuse is configured to burn at approximately 1 foot per minute to approximately 2 feet per minute when ignited. 
     
     
       12. A method comprising:
 depositing a sand composition to form a first portion of a sand core body, wherein the sand composition includes sand and a binder; 
 depositing a burnable fuse on the first portion of the sand core body along a path; 
 depositing the sand composition over the burnable fuse and first portion to form a second portion of the sand core body, wherein the first portion and the second portion to form the core body and the burnable fuse extends along the path within the core body and out of a surface of the core body; and 
 igniting the burnable fuse such that the fuse burns at approximately 1 foot per minute or greater and the burning propagates along a length of the fuse within the sand core body to substantially remove the fuse to form a venting tunnel along the path within the sand core body with an opening in the surface. 
 
     
     
       13. The method of  claim 12 , further comprising pouring a molten metal around a portion of the sand core body, wherein gas generated within the sand core body while the molten metal is around the portion of the sand core body escapes the sand core body via the venting tunnel rather than into the molten metal. 
     
     
       14. The method of  claim 12 , wherein igniting the burnable fuse comprises burning the burnable fuse along substantially an entire length of the burnable fuse within the sand core body. 
     
     
       15. The method of  claim 12 , wherein the venting tunnel has substantially a same diameter as the burnable fuse. 
     
     
       16. The method of  claim 12 , wherein the path of the burnable fuse is non-linear. 
     
     
       17. The method of  claim 12 , wherein the burnable fuse comprises a black powder core and at least one outer layer around the black powder core. 
     
     
       18. The method of  claim 12 , wherein the path of the burnable fuse extends in substantially a center of the sand core body. 
     
     
       19. The method of  claim 12 , wherein the burnable fuse extends out of the surface at a first location and a second location such that the venting tunnel formed by burning the fuse includes two separate openings in the surface. 
     
     
       20. The method of  claim 12 , wherein the burnable fuse exhibits a diameter of greater than approximately 1.5 millimeters. 
     
     
       21. The method of  claim 12 , wherein the burnable fuse comprises a fuel source and an oxidizer. 
     
     
       22. The method of  claim 12 , wherein igniting the burnable fuse such that the fuse burns at approximately 1 foot per minute or greater comprises igniting the burnable fuse such that the fuse burns at approximately 1 foot per minute to approximately 2 feet per minute.